1. Field of the Invention
The present invention relates to an improved anti-terrorist and security barrier for use in stopping the movement of vehicles. The device is employed to control access to entranceways, driveways, and roads and to secure a security perimeter around buildings and objects requiring such protection. The device consists of a telescoping bollard inserted into a foundation casing imbedded below ground. The device is manually retracted, is extended by a lift element comprising multi-spring lift mechanism and contains a locking mechanism for securing the telescoping bollard in the extended and retracted positions. When in the retracted position the bollard is flush with the surface and can be traversed by a vehicle.
2. Description of the Related Art
Various security devices employed to control access to entranceways have been proposed. Often found are articulating devices, which consists of an arm or barrier that is pivotally connected to a hydraulic base. The arm or barrier when employed is then raised from a horizontal blocking position to a vertical open position. U.S. Pat. No. 4,858,328 issued to Ellgass is one such device. A disadvantage of such devices is that they are not of reinforced construction and as such cannot arrest the movement of a vehicle. Additionally, such devices are exposed above ground making them subject to vandalism and excessive damage from vehicles hitting them and therefore require frequent repair or replacement.
U.S. Pat. No. 4,576,508 issued to Dickenson is described as an anti-terror barricade capable of stopping the movement of vehicles. This art employs a below the surface bollard raised by a hydraulic lift mechanism. The hydraulic lift mechanism is activated through an electrical control system. Underground environmental exposure to a subterranean electronic device and subterranean hydraulic system is undesirable. Maintenance for hydraulic systems is also very extensive and expensive. Operation based upon two dependent power sources (electrical power and hydraulic power) degrades reliability.
U.S. Pat. No. 4,715,742 issued to Dickinson is also an anti-terror barricade intended to stop the movement of vehicles. This below the surface bollard is raised by the stored energy of a metal coil compression spring. The coil spring is released and locked through an electronically or manually engaged bolt. The bolt and the control box, which houses the bolt, are recessed just below grade level. Access to the control is through a locked cover. Both the bolt and the cover to the control box are located too close to the surface and could result in sabotage or vandalism to the device. This device is flirther disadvantaged in that it relies on a single spring as a lift mechanism and additionally since it can be manually raised it is inherently of lighter construction.
U.S. Pat. No. 4,577,991 issued to Rolow is a vehicle barricade apparatus for arresting the movement of vehicles. These devices as well as the two Dickinson patents above are disadvantaged in that they are intended to be employed instantaneously in the event of a terrorist attack. They are dependent upon the decision of a human to activate the device and are all dependent upon a single lift means without a redundancy capability.
Other prior art include systems that employ bollards encased below the surface. U.S. Pat. No. 4,919,563 issued to Stice and U.S. Pat. No. 5,476,338 issued to Alberts are exemplary of this art. The Stice and Alberts devices are relatively complicated employing a worm gear/screw lift mechanisms and are dependent upon underground motors and external power sources (Electrical Current or Battery) for their operation. Underground environmental exposure to subterranean electronic devices is undesirable. Both devices contain a large number of parts and components. Maintenance for these types of devices is rather extensive. Both devices are primarily designed to control ingress/egress to entranceways; however, they are of light construction and not intended as anti-terror devices.
Further art also include telescoping posts that are raised exclusively through the stored energy of single pneumatic or hydraulic springs. These devices are affected often by temperature variations. They are disadvantaged, in that in extremely cold temperatures the stored energy of the single spring can be severely degraded to the point where effective operation of the device through the exclusive power of the spring may not be feasible or to the point where an extremely powerful spring is required to operate in cold temperatures. Such a powerful spring would require extreme manual pressure to retract the device making the retraction very difficult.
U.S. patent application Ser. No. 08/967800 (Citylift/Goeken and Pepe) is disadvantaged in that it is not intended to stop the movement of vehicles, but, only to reserve a parking space or control access to entrance ways under non-hostile conditions. As such, this device is not reinforced, and is dependent upon a single gas spring as a lift mechanism.
An object of the present invention is to provide a multi-gas spring lift assisted telescoping anti-terror security bollard that is functional within a wide temperature range, a telescoping bollard that ensures continued operation via a redundant multi-gas spring lift mechanism, a telescoping bollard which displays great strength and stability, and one that is easy to install and operate. Accordingly, there is also a need for such a device that has few parts and is easy to repair.
Another object of the bollard is to provide a device that is extremely sturdy, stable and one which would take a long period of time to defeat thus resulting in the prolonged exposure of someone attemp ting to tamper with the device.
Accordingly, it is an object of the present art to provide a gas spring lift assisted telescoping security bollard that is functional within a wide temperature range.
A further object is to provide a telescoping bollard that displays great strength and stability and provides for continued operation through the employment of a redundant multiple gas spring lift mechanism.
An object of the present invention is to provide a telescoping security bollard that is easy to install and is easy to maintain and reliable in its employment.
A further object of the present invention is to provide a security bollard that is of simple design, has few components, and one that is economically priced.
Still a further object of the present invention is to provide a telescoping bollard that guarantees proper drainage and one that will not have its operation be adversely affected by dirt and debris or extreme climatic conditions.
Finally, it is a further object of the present invention is to present a telescoping security bollard that is locked in both the extended and retracted positions. These and other objects are satisfied by the device of the present invention.